1. Field of the Invention
The present invention relates to apparatus for interconnecting cables in network interface devices and, more particularly, to cable interconnection apparatus which can be removably mounted in network interface devices and which can interconnect coaxial cables and fiber optic cables.
2. Discussion of the Related Art
Network interface devices which interconnect telephone company ("telco") and subscriber lines are known in the art. Those network interface devices also provide overvoltage protection for the telco lines. One example of such a known network interface device is shown in U.S. Pat. No. 4,979,209 issued to Collins et al. on Dec. 18, 1990 and assigned to Keptel, Inc. (hereafter "the Keptel '209 patent"). FIG. 3 of the Keptel '209 patent shows overvoltage protection devices 73, while FIG. 2 shows removable subscriber line modules 91 through 96. Subscriber line modules are also known in the art as subscriber bridge modules.
It is also known in the art to employ network interface devices which not only interconnect telco and subscriber lines but also interconnect coaxial cables and fiber optic cables. An example of such a network interface device is shown in U.S. Pat. No. 5,553,136 issued to Meyerhoefer et al on Sept. 3, 1996 and assigned to TII Industries, Inc. (hereafter "the TII '136 patent"). A "bulkhead-type" interconnection 19 for coaxial cable or fiber optic cable is shown in FIG. 4 and described at column 6, lines 51-54 of the TII '136 patent. See also FIGS. 38 and 39. Such a bulk-head type interconnection is adapted to be permanently mounted in the network interface device and is not readily removable. In contrast, the subscriber bridge modules used to interconnect the telco and subscriber lines are readily removable. See, for example, removably mounted subscriber bridge modules 20 in FIGS. 2 and 4-13 of the TII '136 patent.
It is also known to provide a removable module for interconnecting coaxial cables in a network interface device which contains removable subscriber bridge modules. An example of such a removable interconnection module for coaxial cables is shown in U.S. Pat. No. 5,394,466 to Schneider et al issued Feb. 28, 1995 and assigned to Keptel, Inc. (hereafter "the Keptel '466 patent"). See cable television module 220 in FIGS. 1 and 5 of the Keptel '466 patent. As shown in FIGS. 2 and 3 of the Keptel '466 patent, cable television module 220 is not very practical because its complex construction would make it difficult and expensive to manufacture. Moreover, that cable television module does not readily lend itself to providing overvoltage protection for the coaxial cables.
Therefore, it is an object of the present invention to provide a cable interconnection apparatus for coaxial cables and fiber optic cables which is simple and inexpensive to manufacture and which can be easily installed in and removed from a network interface device.
It is another object of the invention to provide a coaxial cable interconnection apparatus which can be easily installed in and removed from a network interface device and which provides overvoltage protection for the coaxial cables.
It is a further object of the invention to provide a cable interconnection apparatus for coaxial cables and fiber optic cables which can be easily mounted in and removed from network interface devices which also contain removable subscriber bridge modules.
It is a further object of the invention to provide a network interface device with both removable subscriber bridge modules and removable cable interconnection apparatus for coaxial cables and fiber optic cables, the interconnection apparatus being simple and inexpensive to manufacture and being easily installed in and removed from the network interface device.
It is a further object of the invention to provide a network interface device with both removable subscriber bridge modules and removable coaxial cable interface apparatus, the interconnection apparatus being easily installed in and removed from the network interface device and providing overvoltage protection for the coaxial cables.